Water-going vessels are steered in any of a variety of ways. One way--commonly used on seagoing vessels and on larger pleasure craft--is by a separate rudder steering a vessel powered by one, two or more "screws" (propellers). The orientation(s) of the propeller(s) remain unchanged with respect to the vessel hull.
Another way commonly used with smaller pleasure craft is to pivot all or a part of the propulsion system so that the rotational axis of the propeller moves with respect to the vessel hull and its long axis. On so-called inboard-outboard drives, only a portion of the propeller drive train pivots. However, on boats driven by outboard engines, the entire engine (but for its stern mounting bracket and the like) are pivoted on the transom of the boat.
Smaller outboard engines are steered by an operator sitting at the rearmost seat and grasping the engine handle. Such handle not only pivots the engine about a generally vertical axis, it usually includes a twist-type throttle control. Thus, the operator controls vessel speed and direction with one hand.
But for larger outboard engines, hand steering in that manner is impractical. For one thing, the engine is simply too heavy to steer with one hand. And boats large enough to accept such an engine usually have steering and throttle controls at a forward seat location. The operator faces directly forward as when driving an automobile.
Larger outboard engines are often steered using some type of "force-multiplying" mechanism such as a steering wheel and control cable, the latter as made by Morse Controls and others. Or steering may be by hydraulic cylinder systems as made by Hynautic, Sarasota, Fla. In a common arrangement, the cylinder body is mounted in a fixed location and a cylinder rod is coupled to the engine tiller bar by a steering link. In another arrangement, the rods are at a fixed location and the cylinder body is coupled to the tiller bar for bar movement.
Apparatus for boat steering are shown in U.S. Pat. Nos. 2,787,235 (Schroeder); U.S. Pat. No. 4,773,882 (Rump); U.S. Pat. No. 4,836,812 (Griffiths); U.S. Pat. No. 5,340,341 (Yoshimura) and, no doubt, others. A problem faced by outboard engine builders and designers of cylinder-equipped hydraulic steering systems is the matter of mounting the cylinder with respect to the engine. The problem is very evident from an analysis of the noted patents.
In the arrangement disclosed in the Griffiths patent, the center bracket on which the steering cylinder is rigidly mounted is, itself, rigidly attached to the steering arm of the primary engine. The arrangement assumes that such steering arm includes mounting holes or, dismayingly, the boat builder or user must provide such holes.
The steering assembly shown in the Rump patent uses a cylinder with a projecting tongue that pivotably pins to the engine tiller arm. Like that of the Griffiths patent, the Rump arrangement seemingly assumes that the tiller arm comes equipped with a mounting hole.
The arrangements shown in U.S. Pat. No. 2,855,755 (Auger) and in the Schroeder and Yoshimura patents "sidestep" the matter of closely-coupling the cylinder and the engine to one another. Instead, the cylinder is mounted some distance from the engine and long linkages are used to connect the two together. In that way, the cylinder designer can ignore the differing mounting provisions configured by the engine manufacturers.
But these arrangements tend to be (in the vernacular) "Rube-Goldberg-like." Manufacturing boat and engine builders are not likely to be enthusiastic about them, at least because they are aesthetically lacking. And some arrangements are seemingly very time-consuming to mount. (Of course, extended assembly time translates into extended manufactured cost, selling price and, later, difficulty in repair.)
Known prior art mounting arrangements which space the steering cylinder well away from the engine being steered simplify the task of the designer of such mounting arrangements in another way. One need not fit a mounting bracket to avoid such seemingly-innocuous but critical appurtenances as "Zerk" grease fittings for lubricating the tilt tube. (Zerk type grease fittings are well known, are installed on, inter alia, passenger autos and are configured for use with a pressurized grease gun.)
Another disadvantage of prior art arrangements like those of the Schroeder, Auger and Griffiths patents involves the bolting arrangement. The forces imposed on the bolts are shear forces and it is only (or substantially only) shear forces that secure the mounting bracket and the cylinder with respect to one another. To put it in other words, these prior art arrangements do not appreciate how to configure a mounting bracket to substantially avoid imposing shear forces upon the securing bolts.
Yet another disadvantage of prior art arrangements is that they are not invertible in use. In other words, they can be used in but a single orientation. Such arrangements fail to appreciate how a mounting bracket can be configured to be invertible so as to adapt to a variety of brands of engines.
The fact that prior workers in the field have sidestepped the problem of trying to directly mount a hydraulic steering cylinder to any of a variety of outboard engines is not surprising--the problem has persisted for some years and is not easy to solve. "Single-use" mounting brackets make the work of the boat builder (or of the company mounting an engine to a boat) more difficult. This is so because such builder or company must stock a variety of mounting brackets, at least one for each brand of outboard engine anticipated to be equipped with a steering cylinder.
The invention offers a bold and imaginative solution to the matter of cylinder/engine mounting. Details regarding such invention are set forth below.